text: /*-
   * Copyright (c) 2012 EMC Corp.
   * All rights reserved.
   *
   * Copyright (c) 1997, 1998 Justin T. Gibbs.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  #include <sys/cdefs.h>
  __FBSDID("$FreeBSD$");
  
  #include "opt_bus.h"
  
  #include <sys/param.h>
  #include <sys/conf.h>
  #include <sys/systm.h>
  #include <sys/bio.h>
  #include <sys/bus.h>
  #include <sys/callout.h>
  #include <sys/mbuf.h>
  #include <sys/memdesc.h>
  #include <sys/proc.h>
  #include <sys/uio.h>
  
  #include <vm/vm.h>
  #include <vm/vm_page.h>
  #include <vm/vm_map.h>
  #include <vm/pmap.h>
  
  #include <cam/cam.h>
  #include <cam/cam_ccb.h>
  
  #include <machine/bus.h>
  
  /*
   * Load up data starting at offset within a region specified by a
   * list of virtual address ranges until either length or the region
   * are exhausted.
   */
  static int
  _bus_dmamap_load_vlist(bus_dma_tag_t dmat, bus_dmamap_t map,
      bus_dma_segment_t *list, int sglist_cnt, struct pmap *pmap, int *nsegs,
      int flags, size_t offset, size_t length)
  {
  	int error;
  
  	error = 0;
  	for (; sglist_cnt > 0 && length != 0; sglist_cnt--, list++) {
  		char *addr;
  		size_t ds_len;
  
  		KASSERT((offset < list->ds_len),
  		    ("Invalid mid-segment offset"));
  		addr = (char *)(uintptr_t)list->ds_addr + offset;
  		ds_len = list->ds_len - offset;
  		offset = 0;
  		if (ds_len > length)
  			ds_len = length;
  		length -= ds_len;
  		KASSERT((ds_len != 0), ("Segment length is zero"));
  		error = _bus_dmamap_load_buffer(dmat, map, addr, ds_len, pmap,
  		    flags, NULL, nsegs);
  		if (error)
  			break;
  	}
  	return (error);
  }
  
  /*
   * Load a list of physical addresses.
   */
  static int
  _bus_dmamap_load_plist(bus_dma_tag_t dmat, bus_dmamap_t map,
      bus_dma_segment_t *list, int sglist_cnt, int *nsegs, int flags)
  {
  	int error;
  
  	error = 0;
  	for (; sglist_cnt > 0; sglist_cnt--, list++) {
  		error = _bus_dmamap_load_phys(dmat, map,
  		    (vm_paddr_t)list->ds_addr, list->ds_len, flags, NULL,
  		    nsegs);
  		if (error)
  			break;
  	}
  	return (error);
  }
  
  /*
   * Load an mbuf chain.
   */
  static int
  _bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
      struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, int flags)
  {
  	struct mbuf *m;
  	int error;
  
  	error = 0;
  	for (m = m0; m != NULL && error == 0; m = m->m_next) {
  		if (m->m_len > 0) {
  			error = _bus_dmamap_load_buffer(dmat, map, m->m_data,
  			    m->m_len, kernel_pmap, flags | BUS_DMA_LOAD_MBUF,
  			    segs, nsegs);
  		}
  	}
  	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  	    __func__, dmat, flags, error, *nsegs);
  	return (error);
  }
  
  /*
   * Load from block io.
   */
  static int
  _bus_dmamap_load_bio(bus_dma_tag_t dmat, bus_dmamap_t map, struct bio *bio,
      int *nsegs, int flags)
  {
  
  	if ((bio->bio_flags & BIO_VLIST) != 0) {
  		bus_dma_segment_t *segs = (bus_dma_segment_t *)bio->bio_data;
  		return (_bus_dmamap_load_vlist(dmat, map, segs, bio->bio_ma_n,
  		    kernel_pmap, nsegs, flags, bio->bio_ma_offset,
  		    bio->bio_bcount));
  	}
  
  	if ((bio->bio_flags & BIO_UNMAPPED) != 0)
  		return (_bus_dmamap_load_ma(dmat, map, bio->bio_ma,
  		    bio->bio_bcount, bio->bio_ma_offset, flags, NULL, nsegs));
  
  	return (_bus_dmamap_load_buffer(dmat, map, bio->bio_data,
  	    bio->bio_bcount, kernel_pmap, flags, NULL, nsegs));
  }
  
  int
  bus_dmamap_load_ma_triv(bus_dma_tag_t dmat, bus_dmamap_t map,
      struct vm_page **ma, bus_size_t tlen, int ma_offs, int flags,
      bus_dma_segment_t *segs, int *segp)
  {
  	vm_paddr_t paddr;
  	bus_size_t len;
  	int error, i;
  
  	error = 0;
  	for (i = 0; tlen > 0; i++, tlen -= len) {
  		len = min(PAGE_SIZE - ma_offs, tlen);
  		paddr = VM_PAGE_TO_PHYS(ma[i]) + ma_offs;
  		error = _bus_dmamap_load_phys(dmat, map, paddr, len,
  		    flags, segs, segp);
  		if (error != 0)
  			break;
  		ma_offs = 0;
  	}
  	return (error);
  }
  
  /*
   * Load a cam control block.
   */
  static int
  _bus_dmamap_load_ccb(bus_dma_tag_t dmat, bus_dmamap_t map, union ccb *ccb,
  		    int *nsegs, int flags)
  {
  	struct ccb_hdr *ccb_h;
  	void *data_ptr;
  	int error;
  	uint32_t dxfer_len;
  	uint16_t sglist_cnt;
  
  	error = 0;
  	ccb_h = &ccb->ccb_h;
  	switch (ccb_h->func_code) {
  	case XPT_SCSI_IO: {
  		struct ccb_scsiio *csio;
  
  		csio = &ccb->csio;
  		data_ptr = csio->data_ptr;
  		dxfer_len = csio->dxfer_len;
  		sglist_cnt = csio->sglist_cnt;
  		break;
  	}
  	case XPT_CONT_TARGET_IO: {
  		struct ccb_scsiio *ctio;
  
  		ctio = &ccb->ctio;
  		data_ptr = ctio->data_ptr;
  		dxfer_len = ctio->dxfer_len;
  		sglist_cnt = ctio->sglist_cnt;
  		break;
  	}
  	case XPT_ATA_IO: {
  		struct ccb_ataio *ataio;
  
  		ataio = &ccb->ataio;
  		data_ptr = ataio->data_ptr;
  		dxfer_len = ataio->dxfer_len;
  		sglist_cnt = 0;
  		break;
  	}
  	default:
  		panic("_bus_dmamap_load_ccb: Unsupported func code %d",
  		    ccb_h->func_code);
  	}
  
  	switch ((ccb_h->flags & CAM_DATA_MASK)) {
  	case CAM_DATA_VADDR:
  		error = _bus_dmamap_load_buffer(dmat, map, data_ptr, dxfer_len,
  		    kernel_pmap, flags, NULL, nsegs);
  		break;
  	case CAM_DATA_PADDR:
  		error = _bus_dmamap_load_phys(dmat, map,
  		    (vm_paddr_t)(uintptr_t)data_ptr, dxfer_len, flags, NULL,
  		    nsegs);
  		break;
  	case CAM_DATA_SG:
  		error = _bus_dmamap_load_vlist(dmat, map,
  		    (bus_dma_segment_t *)data_ptr, sglist_cnt, kernel_pmap,
  		    nsegs, flags, 0, dxfer_len);
  		break;
  	case CAM_DATA_SG_PADDR:
  		error = _bus_dmamap_load_plist(dmat, map,
  		    (bus_dma_segment_t *)data_ptr, sglist_cnt, nsegs, flags);
  		break;
  	case CAM_DATA_BIO:
  		error = _bus_dmamap_load_bio(dmat, map, (struct bio *)data_ptr,
  		    nsegs, flags);
  		break;
  	default:
  		panic("_bus_dmamap_load_ccb: flags 0x%X unimplemented",
  		    ccb_h->flags);
  	}
  	return (error);
  }
  
  /*
   * Load a uio.
   */
  static int
  _bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
      int *nsegs, int flags)
  {
  	bus_size_t resid;
  	bus_size_t minlen;
  	struct iovec *iov;
  	pmap_t pmap;
  	caddr_t addr;
  	int error, i;
  
  	if (uio->uio_segflg == UIO_USERSPACE) {
  		KASSERT(uio->uio_td != NULL,
  			("bus_dmamap_load_uio: USERSPACE but no proc"));
  		pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
  	} else
  		pmap = kernel_pmap;
  	resid = uio->uio_resid;
  	iov = uio->uio_iov;
  	error = 0;
  
  	for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
  		/*
  		 * Now at the first iovec to load.  Load each iovec
  		 * until we have exhausted the residual count.
  		 */
  
  		addr = (caddr_t) iov[i].iov_base;
  		minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len;
  		if (minlen > 0) {
  			error = _bus_dmamap_load_buffer(dmat, map, addr,
  			    minlen, pmap, flags, NULL, nsegs);
  			resid -= minlen;
  		}
  	}
  
  	return (error);
  }
  
  /*
   * Map the buffer buf into bus space using the dmamap map.
   */
  int
  bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
      bus_size_t buflen, bus_dmamap_callback_t *callback,
      void *callback_arg, int flags)
  {
  	bus_dma_segment_t *segs;
  	struct memdesc mem;
  	int error;
  	int nsegs;
  
  	if ((flags & BUS_DMA_NOWAIT) == 0) {
  		mem = memdesc_vaddr(buf, buflen);
  		_bus_dmamap_waitok(dmat, map, &mem, callback, callback_arg);
  	}
  
  	nsegs = -1;
  	error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, kernel_pmap,
  	    flags, NULL, &nsegs);
  	nsegs++;
  
  	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  	    __func__, dmat, flags, error, nsegs);
  
  	if (error == EINPROGRESS)
  		return (error);
  
  	segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  	if (error)
  		(*callback)(callback_arg, segs, 0, error);
  	else
  		(*callback)(callback_arg, segs, nsegs, 0);
  
  	/*
  	 * Return ENOMEM to the caller so that it can pass it up the stack.
  	 * This error only happens when NOWAIT is set, so deferral is disabled.
  	 */
  	if (error == ENOMEM)
  		return (error);
  
  	return (0);
  }
  
  int
  bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
      bus_dmamap_callback2_t *callback, void *callback_arg, int flags)
  {
  	bus_dma_segment_t *segs;
  	int nsegs, error;
  
  	M_ASSERTPKTHDR(m0);
  
  	flags |= BUS_DMA_NOWAIT;
  	nsegs = -1;
  	error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, NULL, &nsegs, flags);
  	++nsegs;
  
  	segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  	if (error)
  		(*callback)(callback_arg, segs, 0, 0, error);
  	else
  		(*callback)(callback_arg, segs, nsegs, m0->m_pkthdr.len, error);
  
  	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  	    __func__, dmat, flags, error, nsegs);
  	return (error);
  }
  
  int
  bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
      bus_dma_segment_t *segs, int *nsegs, int flags)
  {
  	int error;
  
  	flags |= BUS_DMA_NOWAIT;
  	*nsegs = -1;
  	error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, segs, nsegs, flags);
  	++*nsegs;
  	_bus_dmamap_complete(dmat, map, segs, *nsegs, error);
  	return (error);
  }
  
  int
  bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
      bus_dmamap_callback2_t *callback, void *callback_arg, int flags)
  {
  	bus_dma_segment_t *segs;
  	int nsegs, error;
  
  	flags |= BUS_DMA_NOWAIT;
  	nsegs = -1;
  	error = _bus_dmamap_load_uio(dmat, map, uio, &nsegs, flags);
  	nsegs++;
  
  	segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  	if (error)
  		(*callback)(callback_arg, segs, 0, 0, error);
  	else
  		(*callback)(callback_arg, segs, nsegs, uio->uio_resid, error);
  
  	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  	    __func__, dmat, flags, error, nsegs);
  	return (error);
  }
  
  int
  bus_dmamap_load_ccb(bus_dma_tag_t dmat, bus_dmamap_t map, union ccb *ccb,
  		    bus_dmamap_callback_t *callback, void *callback_arg,
  		    int flags)
  {
  	bus_dma_segment_t *segs;
  	struct ccb_hdr *ccb_h;
  	struct memdesc mem;
  	int error;
  	int nsegs;
  
  	ccb_h = &ccb->ccb_h;
  	if ((ccb_h->flags & CAM_DIR_MASK) == CAM_DIR_NONE) {
  		callback(callback_arg, NULL, 0, 0);
  		return (0);
  	}
  	if ((flags & BUS_DMA_NOWAIT) == 0) {
  		mem = memdesc_ccb(ccb);
  		_bus_dmamap_waitok(dmat, map, &mem, callback, callback_arg);
  	}
  	nsegs = -1;
  	error = _bus_dmamap_load_ccb(dmat, map, ccb, &nsegs, flags);
  	nsegs++;
  
  	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  	    __func__, dmat, flags, error, nsegs);
  
  	if (error == EINPROGRESS)
  		return (error);
  
  	segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  	if (error)
  		(*callback)(callback_arg, segs, 0, error);
  	else
  		(*callback)(callback_arg, segs, nsegs, error);
  	/*
  	 * Return ENOMEM to the caller so that it can pass it up the stack.
  	 * This error only happens when NOWAIT is set, so deferral is disabled.
  	 */
  	if (error == ENOMEM)
  		return (error);
  
  	return (0);
  }
  
  int
  bus_dmamap_load_bio(bus_dma_tag_t dmat, bus_dmamap_t map, struct bio *bio,
  		    bus_dmamap_callback_t *callback, void *callback_arg,
  		    int flags)
  {
  	bus_dma_segment_t *segs;
  	struct memdesc mem;
  	int error;
  	int nsegs;
  
  	if ((flags & BUS_DMA_NOWAIT) == 0) {
  		mem = memdesc_bio(bio);
  		_bus_dmamap_waitok(dmat, map, &mem, callback, callback_arg);
  	}
  	nsegs = -1;
  	error = _bus_dmamap_load_bio(dmat, map, bio, &nsegs, flags);
  	nsegs++;
  
  	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  	    __func__, dmat, flags, error, nsegs);
  
  	if (error == EINPROGRESS)
  		return (error);
  
  	segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  	if (error)
  		(*callback)(callback_arg, segs, 0, error);
  	else
  		(*callback)(callback_arg, segs, nsegs, error);
  	/*
  	 * Return ENOMEM to the caller so that it can pass it up the stack.
  	 * This error only happens when NOWAIT is set, so deferral is disabled.
  	 */
  	if (error == ENOMEM)
  		return (error);
  
  	return (0);
  }
  
  int
  bus_dmamap_load_mem(bus_dma_tag_t dmat, bus_dmamap_t map,
      struct memdesc *mem, bus_dmamap_callback_t *callback,
      void *callback_arg, int flags)
  {
  	bus_dma_segment_t *segs;
  	int error;
  	int nsegs;
  
  	if ((flags & BUS_DMA_NOWAIT) == 0)
  		_bus_dmamap_waitok(dmat, map, mem, callback, callback_arg);
  
  	nsegs = -1;
  	error = 0;
  	switch (mem->md_type) {
  	case MEMDESC_VADDR:
  		error = _bus_dmamap_load_buffer(dmat, map, mem->u.md_vaddr,
  		    mem->md_opaque, kernel_pmap, flags, NULL, &nsegs);
  		break;
  	case MEMDESC_PADDR:
  		error = _bus_dmamap_load_phys(dmat, map, mem->u.md_paddr,
  		    mem->md_opaque, flags, NULL, &nsegs);
  		break;
  	case MEMDESC_VLIST:
  		error = _bus_dmamap_load_vlist(dmat, map, mem->u.md_list,
  		    mem->md_opaque, kernel_pmap, &nsegs, flags, 0, SIZE_T_MAX);
  		break;
  	case MEMDESC_PLIST:
  		error = _bus_dmamap_load_plist(dmat, map, mem->u.md_list,
  		    mem->md_opaque, &nsegs, flags);
  		break;
  	case MEMDESC_BIO:
  		error = _bus_dmamap_load_bio(dmat, map, mem->u.md_bio,
  		    &nsegs, flags);
  		break;
  	case MEMDESC_UIO:
  		error = _bus_dmamap_load_uio(dmat, map, mem->u.md_uio,
  		    &nsegs, flags);
  		break;
  	case MEMDESC_MBUF:
  		error = _bus_dmamap_load_mbuf_sg(dmat, map, mem->u.md_mbuf,
  		    NULL, &nsegs, flags);
  		break;
  	case MEMDESC_CCB:
  		error = _bus_dmamap_load_ccb(dmat, map, mem->u.md_ccb, &nsegs,
  		    flags);
  		break;
  	}
  	nsegs++;
  
  	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  	    __func__, dmat, flags, error, nsegs);
  
  	if (error == EINPROGRESS)
  		return (error);
  
  	segs = _bus_dmamap_complete(dmat, map, NULL, nsegs, error);
  	if (error)
  		(*callback)(callback_arg, segs, 0, error);
  	else
  		(*callback)(callback_arg, segs, nsegs, 0);
  
  	/*
  	 * Return ENOMEM to the caller so that it can pass it up the stack.
  	 * This error only happens when NOWAIT is set, so deferral is disabled.
  	 */
  	if (error == ENOMEM)
  		return (error);
  
  	return (0);
  }
  